Prehospital treatment of hyperkalaemia

Abstract

This article explores the assessment and management considerations of patients with hyperkalaemia. Using a case study from clinical practice, the hospital treatment is reviewed with particular emphasis upon the use of calcium, insulin and dextrose. In particular, potential prehospital treatments are considered, with focus upon the use of salbutamol and furosemide. Definitions, incidence and mortality rates of hyperkalaemia are also detailed. The signs, symptoms and causes of the condition are examined, with the aim of achieving prehospital diagnosis in the absence of serum potassium levels. Hyperkalaemic electrocardiogram (ECG) changes are studied and examples are given. Conclusions are made, including a recommendation for the prehospital use of salbutamol in the treatment of hyperkalaemia. (Khedr et al, 2009). A clear understanding of the emergency management is crucial as hyperkalaemia has lethal consequences and is associated with a mortality rate of 14-41% (Feld and Kaskel, 2010). Furthermore, severe hyperkalaemia, if not treated rapidly, carries a mortality rate of 67% (Weisberg, 2008), providing a compelling argument for treating the condition in the prehospital phase. Key wordsl Diagnosis Signs and symptomsTo carry out appropriate management of hyperkalaemic patients, an understanding of the signs and symptoms is fundamental. An increased concentration of potassium in the plasma has the effect of depolarizing cell membranes, therefore making them less excitable and in turn, resulting in neuromuscular dysfunction (Lubin et al, 2006). Patients with hyperkalaemia can display abnormal signs and symptoms specific to the renal, gastrointestinal, cardiovascular and nervous systems (LeFever Kee et al, 2009). They can present with nausea, abdominal pain and or/diarrhoea (Guy, 2009); but also muscle irritability, malaise, muscle weakness and, in patients with serum potassium levels of greater than 6.0 mEq/L, paresthesia and an increased heart rate (LeFever Kee et al, 2009).Despite such an array of symptoms, it is commonly documented that, even with severe hyperkalaemia, patients can present with no abnormalities (Gleadle, 2007;Baltazar, 2009). This would explain Mrs Y's asymptomatic presentation, making diagnosing the condition in the prehospital environment difficult, if not impossible. BloodsIn Mrs Y's case, the diagnosis had been made on the basis of blood results and a history of reduced renal function-a well recognized cause of hyperkalaemia (Irwin and Rippe, 2008). In the presence of normal renal function, the attending doctor would suspect 'pseudohyperkalaemia', a condition in which abnormal potassium levels are the result of haemolysis in-vitro (Irwin and Rippe, 2008). However, such factors are not of concern to UK paramedics as, despite evidence-based approval (Prause et al, 1997), blood gas and electrolyte testing is currently unavailable in the prehospital stage. The ECGWithout the help of serum potassium results and without the benefit of specific signs and symptoms, diagnosing hyperkalaemia in...